MK Diamond Baldor Motor - Manual (Page 7)

General Information 1-3 MN408
Storage
Storage requirements for motors and generators that will not be placed in service for at least six months from
date of shipment.
Improper motor storage will result in seriously reduced reliability and failure. An electric motor that does not
experience regular usage while being exposed to normally humid atmospheric conditions is likely to develop
rust in the bearings or rust particles from surrounding surfaces may contaminate the bearings. The electrical
insulation may absorb an excessive amount of moisture leading to the motor winding failure.
A wooden crate “shell” should be constructed to secure the motor during storage. This is similar to an export
box but the sides & top must be secured to the wooden base with lag bolts (not nailed as export boxes are) to
allow opening and reclosing many times without damage to the “shell”.
Minimum resistance of motor winding insulation is 5 Meg ohms or the calculated minimum, which ever is
greater. Minimum resistance is calculated as follows: Rm = kV + 1
where: (Rm is minimum resistance to ground in Meg−Ohms and kV is rated nameplate
voltage defined as Kilo−Volts.)
Example: For a 480VAC rated motor Rm =1.48 meg−ohms (use 5 M Ω).
For a 4160VAC rated motor Rm = 5.16 meg−ohms.
Preparation for Storage
1. Some motors have a shipping brace attached to the shaft to prevent damage during transportation.
The shipping brace, if provided, must be removed and stored for future use. The brace must be reinstalled
to hold the shaft firmly in place against the bearing before the motor is moved.
2. Store in a clean, dry, protected warehouse where control is maintained as follows:
a. Shock or vibration must not exceed 2 mils maximum at 60 hertz, to prevent the bearings from
brinelling. If shock or vibration exceeds this limit vibration isolation pads must be used.
b. Storage temperatures of 10 ºC (50 ºF) to 49 ºC (120 ºF) must be maintained.
c. Relative humidity must not exceed 60%.
d. Motor space heaters (when present) are to be connected and energized whenever there is a possibility
that the storage ambient conditions will reach the dew point. Space heaters are optional.
Note: Remove motor from containers when heaters are energized, reprotect if necessary.
3. Measure and record the resistance of the winding insulation (dielectric withstand) every 30 days of storage.
a. If motor insulation resistance decreases below the minimum resistance, contact your Baldor District
office.
b. Place new desiccant inside the vapor bag and re−seal by taping it closed.
c. If a zipper−closing type bag is used instead of the heat−sealed type bag, zip the bag closed instead
of taping it. Be sure to place new desiccant inside bag after each monthly inspection.
d. Place the shell over the motor and secure with lag bolts.
4. Where motors are mounted to machinery, the mounting must be such that the drains and breathers are
fully operable and are at the lowest point of the motor. Vertical motors must be stored in the vertical
position. Storage environment must be maintained as stated in step 2.
5. Motors with anti−friction bearings are to be greased at the time of going into extended storage with
periodic service as follows:
a. Motors marked “Do Not Lubricate” on the nameplate do not need to be greased before or during
storage.
b. Ball and roller bearing (anti−friction) motor shafts are to be rotated manually every 3 months and
greased every 6 months in accordance with the Maintenance section of this manual.
c. Sleeve bearing (oil lube) motors are drained of oil prior to shipment. The oil reservoirs must be refilled
to the indicated level with the specified lubricant, (see Maintenance). The shaft should be rotated
monthly by hand at least 10 to 15 revolutions to distribute oil to bearing surfaces.
d. “Provisions for oil mist lubrication” – These motors are packed with grease. Storage procedures are
the same as paragraph 5b.
e. “Oil Mist Lubricated” – These bearings are protected for temporary storage by a corrosion inhibitor.
If stored for greater than 3 months or outdoor storage is anticipated, connected to the oil mist
system while in storage. If this is not possible, add the amount of grease indicated under “Standard
Condition” in Section 3, then rotate the shaft 15 times by hand.